An inflatable restraint cushion which is commonly referred to as an airbag housed on a fixed portion of a vehicle body in front of an occupant seat plays an important roll in protecting occupants in the vehicle from injury due to collision against the vehicle body. A vehicle airbag assembly typically includes an inflator and inflatable cushion coupled to the inflator. The inflatable cushion typically includes a gas inlet opening which is positioned to accept inflation fluid from the inflator. A typical airbag assembly will also generally include a cover which is coupled to a container for housing the cushion and which, together with the container, forms a modular receptacle for the cushion. One such airbag assembly is disclosed in U.S. Pat. No. 5,284,358 to Rhein issued Feb. 8, 1994 the teachings of which are incorporated herein by reference.
An airbag assembly is generally attached to a structural portion of the vehicle. By way of example only, the airbag assembly disposed on the passenger side of a typical automobile may be coupled with the support structure for the vehicle instrument panel or dashboard and the cover may form a part of the instrument panel. When coupled with a vehicle, the airbag assembly operates to deploy the airbag at the onset of a vehicle collision. Specifically, a gas generating agent in the inflater induces a chemical reaction by a collision signal from a collision detecting sensor when the deceleration of the vehicle exceeds a certain predetermined level. The inflatable cushion is instantaneously inflated and expanded by the generated reaction gas. Upon deployment and inflation, the inflatable cushion receives a vehicle occupant thrown forward by inertia and thereby protects the vehicle occupant from a secondary collision against the vehicle body. Details regarding cushion deployment and configuration are disclosed in U.S. Pat. No. 4,944,529 to Backhaus issued Jul. 31, 1990; U.S. Pat. No. 5,087,071 to Wallner, et al. issued Feb. 11, 1992; and U.S. Pat. No. 5,090,729 to Watanabe issued Feb. 25, 1992, the teachings of all of which are incorporated herein by reference.
Airbags which are presently used on the driver's side of a vehicle are typically formed by sewing two substantially round sections of material together to provide an expanded barrier between the driver and the steering column. Airbags which have been used to protect vehicle passengers, on the other hand, have typically been formed from rather complex geometric shapes so as to obtain the desired final expanded configuration to properly fit the relatively large space present between the passenger seat and the instrument panel or front windshield. Such practices have lead to inefficiencies regarding the complete utilization of construction materials and complicated sewing practices. In light of these infirmities, there is a need for an airbag which is formed from a small number of material segments which can be sewn or otherwise joined together on a flat surface environment but which can nonetheless be expanded to a sufficiently complex geometry to provide protection to an occupant located in a passenger seat. These needs are addressed by providing an occupant restraint cushion formed by the introduction of lap structures having overlapping interior folds and outboard attachment margins adjacent selected periphery edges to form a folded material blank and thereafter adjoining another section of material to the perimeter of the folded structure along the outboard attachment margins to provide an expansible cushion.